System and method for a photovoltaic system programmable dynamic circuit breaker

ABSTRACT

A photovoltaic array of photovoltaic solar cells; a smart dynamic programmable circuit breaker for electrically providing a pulsed 100 microseconds duration short circuit to the photovoltaic array electrical outputs, wherein a response time for the smart dynamic programmable circuit breaker is more than 1 millisecond when responding to a short circuit; a computer program comprising instructions that when executed by the processor perform functions that control the smart dynamic programmable circuit breaker, the computer program comprising: instructions to command the smart dynamic programmable circuit breaker to initiate the 100 microsecond pulsed short circuit; instructions to measure a current magnitude and current rise time of the smart photovoltaic system outputs during the 100 microsecond pulsed short circuit; and instructions to select a behavior curve from a plurality of smart dynamic programmable circuit breaker behavior curves 10% above the current magnitude and current rise time during the pulsed short circuit.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent applications claims priority from U.S. Provisional PatentApplication Ser. No. 62/964,765 by Janik, entitled “A SYSTEM AND METHODFOR A HYBRID PULSED POWER METER” filed on Jan. 23, 2020, which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Fuses blow to protect circuits from too much current and burning up ordamaging electrical components. There is a need for a circuit breakerfor photovoltaic arrays.

FIELD OF THE INVENTION

Circuit breakers for solar installations.

SUMMARY OF THE INVENTION

A system and method for a hybrid pulsed circuit breakers for solarinstallations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic diagram of an illustrative embodiment of theinvention.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT OF THE INVENTION

Fuses blow to protect circuits from too much current and burning up ordamaging electrical components. This turns out to be very hard to dowith solar installations. So much so, that the major fuse manufacturershad to develop “special”, super sensitive and expensive “solar” fusesfor photovoltaic systems. Thus, there is a need for a circuit breakerfor a photovoltaic system.

If you take a solar panel and hold the wires in your hand open circuit,the panel simply make a low DC Open Circuit voltage. If you touch thewires together into a short circuit, nothing visible happens. No spark,no damage, no nothing. The panel simply makes Short Circuit Current.This is super hard to protect because, unlike rotating machinery likemotors and generators, there is no “extra short circuit current”developed. In rotating equipment, there is a tremendous amount of StoredEnergy in the Electric and Magnetic fields and all of this Energy isreleased when a short circuit occurs. Many times this energy is a shortduration current spike that is 5 to 30 times as much as the full load100% rating. That means that you get a 500% to 3,000% current spike andthis makes it super EASY to blow a fuse or trip a circuit breaker. Also,when connected to a very large utility, there is tremendous energyavailable in the form of Short Circuit Current to blow a fuse or trip acircuit breaker.

In solar systems such a photovoltaic systems (PV systems), there is lesscurrent available to trip a circuit breaker, however, when there is some“stored energy” available, sort of like with the electric and magneticfields of rotating machines, but with batteries in this case, circuitprotection is easier to accomplish.

In a particular illustrative embodiment of the invention, the system andmethod integrates this knowledge of the stored energy available into theprotection circuit. So pulsing the circuit with quick short circuitsintentionally (very short −100 microseconds, shorter than a circuitbreaker's reaction time on the order of milliseconds), a processormonitors the impedance and short circuit current rise time tointerpolate the realizable short circuit coordination curves that areapplicable for the photovoltaic system. The 100 nano seconds pulseduration is too fast to trip a breaker that typically requiresmilliseconds to react to the nanoseconds long pulse. The system andmethod use the microseconds duration pulse to determine how much currentthe system is responding to set the breaking point trip (trigger) pointvoltage and overcurrent. The circuit breaker trip or trigger voltage andovercurrent are lowered to reduce the time for the circuit breaker toopen the circuit and break sooner, substantially lowering the time thecircuit breaker reacts to the lowered trigger voltage. The availablecurrent from the PV system varies over time and is sample periodicallyto stay informed of how much current to which the system is respondingand the circuit breaker trip voltage set at the current level at whichthe circuit is responding during the microsecond short circuit pulse.

Turning now to FIG. 1, in a particular illustrative embodiment of theinvention, a photovoltaic system 100 including but not limited to aphotovoltaic array of photovoltaic cells (also referred to herein as“solar cells”) 109 mounted on a photo reactive back plane 105, a powerstorage battery 104 and a programmable dynamic circuit breaker 107comprising a short circuit pulse device 108 and a programmable circuitbreaker 106 are provided. A processor 110 connected to a computerreadable medium 112 containing instructions executed by the processor isalso provided that controls the programmable dynamic circuit breaker.The processor commands the dynamic programmable circuit breaker togenerate a pulsed 100 microsecond circuit between output terminals 114and 116 from the solar array. An inverter 111 is provided sharing thesame circuit breaker and batter with the PV system. The battery providespower in the solar array so that the short circuit generates a shortcircuit current which the processor senses. The current generated by thePV array of solar cells is also sensed during the short circuit pulse.The processor also senses the voltage output from the PV system and animpedance of the PV system. The pulsed short circuit has a duration thatis an order of magnitude faster than a response time for the circuitbreaker. For example, in a particular illustrative embodiment, for adynamic programmable circuit breaker response time of 1 millisecond, thepulsed short circuit has a duration of 100 microseconds. The 100microsecond pulsed short circuit enables the processor to measure theovercurrent caused by the pulsed short circuit and the rise time of theovercurrent during the pulsed short circuit. In another particularembodiment, the pulsed short circuit duration is adjusted to be longerduration to allow inductive and capacitive elements in the PV system tosettle in electrically as long as the pulsed short circuit duration isshort enough to prevent tripping the dynamic programmable circuitbreaker.

A default for a dynamic programmable circuit breakers is typically 150%to 500% of the normal operating current for the solar array. Theprocessor lowers the overcurrent tripping value down to 10% above thepulsed short circuit overcurrent measured during the pulsed shortcircuit. The lowered overcurrent tripping value enables the dynamicprogrammable circuit breakers to react faster to an actual short circuitin the PV system and better protects the solar array and attachedelectrical components during a short circuit by reacting faster than thecircuit breaker would be able to react at the default setting. The risetime of the pulsed overcurrent is measured and the delay time for theelectronic circuit breaker is adjusted to 10% longer than the rise timeto quicken the response of the circuit breaker to an overcurrent.

Dynamic programmable circuit breakers provide programmable and basicadjustable tripping settings. Each of these adjustable settings actuallyshape the time-current curve of a circuit breaker and enable improvedtripping according to the current impedance of a photovoltaic arrayhaving a photo reactive backplane. In a particular illustrativeembodiment of the invention, the photoreactive backplane reflects,retains, and emits light that passed by photovoltaic cells mounted onthe photo reactive backplane.

The voltage output, current output, and impedance of a photo voltaicsystem (PV system) having a battery and circuit breaker varies with theamount of current being output by the PV system. The amount of currentoutput from the PV system varies with the amount of sunlight strikingthe PV system PV array of solar cells and the level of charge on thebattery or electrical power storage unit in the PV system. The moresunlight striking the PV array, the more current and voltage output bythe PV system.

A smart dynamic programmable circuit breakers is provided in aparticular illustrative embodiment of the invention to protect the PVsystem from damage due to short circuits. In a particular illustrativeembodiment of the invention, a processor provides a command to the smartdynamic circuit breaker to initiate a short circuit pulse duration thatis significantly shorter duration than a reaction time of the circuitbreaker. Thus, the processor produces the short circuit and measures theimpedance of the PV system along with the rise time and magnitude ofcurrent generated in the PV systems due to the short circuit. Theimpedance, voltage and short circuit current for the PV systems variesover time based on the amount of sunlight hitting the PV system. In aparticular embodiment of the invention the short circuit pulse is 100microseconds for a circuit breaker with a minimum reaction time of 500milliseconds. The processor determines the impedance, current magnitudeand current rise time of the short circuit current adjusts the dynamicprogrammable circuit breaker to match the short circuit behavior of thePV system to provide a quicker breaker response time under varying PVsystem conditions that affect the short circuit behavior rise time alsoreferred to herein as a characteristic curve.

In adjusting the behavior of the programmable dynamic circuit breakerthe processor adjust the tripping parameters to match the PV systemcharacteristic short circuit current response curve at the current time,during a changing impedance and short circuit profile for the PV system.Each circuit breaker has a family of behavior curves that are agraphical representation of the circuit breaker's response to aparticular current level and the circuit breaker's response behavior.The processor picks the circuit breaker response time behavior curvethat most closely matches the PV system's short circuit response at agiven time. In a particular illustrative embodiment of the invention,the circuit breakers response time behavior is selected for a trippingvoltage 10% above the short circuit current and 10% above the rise timeof the short circuit. The processor samples the short circuit responseof the PV system periodically and periodically adjusts the response timebehavior of the smart dynamic circuit breaker that matches one of aplurality of behavior curves for the smart dynamic circuit breaker.

In another particular illustrative embodiment of the invention, theprogrammable dynamic circuit breaker has programmable parameters thatinclude but are not limited to Continuous Amps (Ir). Long-Time Delay,Short-Time Pickup, Short-Time Delay, Instantaneous Pickup and GroundFault Pickup, which are adjusted based on the characteristic curve forthe smart to match the current short circuit current determined by theprocessor during the periodic short circuits monitored by the processor.Each setting affects the behavior curve for the smart circuit breaker.

In a particular illustrative embodiment of the invention, a batterysystem is mounted near the solar panels but not on the solar panels. Thebattery system is near enough to the PV array to be able to utilize theelectrical infrastructure of the solar inverters, transformers, andcable systems for both the solar panels and the batteries. In aparticular illustrative embodiment of the invention, the battery systemis mounted within 3 feet of the solar panels. As discussed, this couldsave the cost of redundant electrical infrastructure if one system wereused for photovoltaic (PV) Solar Panels and another for the StoredEnergy! Stored Energy does not necessarily need to be in the form of abattery either. In another particular embodiment of the invention, aflywheel is provided to store energy in the PV system. Additional energystorage means can also be used. The other problem is the case withGround Detection. On “normal” electrical installations, one typicallywill “megger” (measure the resistance in ohms of) a motor winding. Forexample, to see if the meg-ohms to ground are high enough to give theoperator confidence that there will not be a short circuit condition toground once the motor is energized. There are “rules of thumb”, as wellas guidelines that are typically used. For example, a company may telltheir electrical department, to NOT energize the motor if it “megs” lessthan 10 Meg-Ohms to ground. This is fine for checking to see if this onecircuit is ok to energize. But what if there are 10 motors connected inparallel (not normal) and they all are “ok” with 10 Meg-Ohms to ground.The one simple measurement will read 10 each, 10 Meg-ohms circuits inparallel and yield a measurement reading of 1 Meg-Ohm even though allmotors are really ok. Now take this to an extreme with 1,000's of solarpanels! Every panel is very insulated from ground with Gig-Ohms toground, but the “SYSTEM” reads a dead short to ground.

The solar panel(s) and battery utilize the same cables, inverters,transformers, and other “solar” infrastructure simultaneously at zeroadditional cost to add stored energy. In a particular illustrativeembodiment of the invention, a battery chemistry that is low cost, lowpower, high energy with no rare earth constituents such as cobalt isused and uses aluminum as a conductor as part of the stored energydesign.

In another particular illustrative embodiment of the invention, the PVarray is mounted on a photoreactive back plane. In a particularembodiment, a highly polished aluminum is used as a reflector on theback plane of the solar panel to reflect escaping photons that havepassed through the top of the solar panel are subsequently reflected bythe reflective back plane and back through the back of the solar panelto increase absorption of photons in the PV array and thereforeefficiency of the PV array (also referred to as a “solar panel”). Thestored energy medium (battery, et al.) can be constructed of a thin filmpolymer that can be applied with a vapor deposition technique, similarto the solar film technology that commercially available First Solaruses to make glass panels. This idea would also give the solar panelmore short circuit current available which would greatly enhance FusibleProtection, presently a very difficult proposition. In anotherparticular embodiment of the invention, a layer of phosphorus (like onan analog oscilloscope having a phosphorescent coating) or StrontiumAluminate is added on the back of a solar panel to “store” the photonicglow for re-harvesting energy of photons stored in phosphorus so thatphotos are re-harvested from the light emitted by the phosphorescentback plane. In addition to storing the energy to “store the light” tomake the PV panels more powerful by adding additional light from thephosphorescent back plane.

Dynamic programmable circuit breakers provide programmable and basicadjustable tripping settings. Each of these adjustable settings actuallyshape the time-current curve of a circuit breaker and enable improvedtripping according to the current impedance of a photovoltaic arrayhaving a photo reactive backplane. The photoreactive phosphorescentbackplane reflects, retains, and emits light that passed by photovoltaiccells mounted on the photo reactive backplane.

The voltage output, current output, and impedance of a photo voltaic(PV) array system (PV system) having a battery and circuit breakervaries with the amount of current being output by the PV array. Theamount of current output from the PV array varies with the amount ofsunlight striking the PV array and the level of charge on the battery orelectrical power storage unit in the PV system. The more sunlightstriking the PV array, the more current and voltage output by the PVsystem.

A programmable dynamic circuit breaker is provided in a particularillustrative embodiment of the invention to protect the PV system fromdamage due to short circuits. In a particular illustrative embodiment ofthe invention, a processor provides a command to the smart dynamiccircuit breaker to initiate a short circuit pulse duration that issignificantly shorter duration than a reaction time of the circuitbreaker. Thus, the processor produces the short circuit and measures theimpedance of the PV system along with the rise time and magnitude ofcurrent generated in the PV systems due to the short circuit. Theimpedance, voltage and short circuit current for the PV systems variesover time based on the amount of sunlight hitting the PV system. In aparticular embodiment of the invention the short circuit pulse is 100microseconds for a circuit breaker with a minimum reaction time of 500milliseconds.

The processor determines the impedance, current magnitude and presentrise time of the short circuit current adjusts the dynamic programmablecircuit breaker to match the short circuit behavior of the PV system toprovide a quicker breaker response time under varying PV systemconditions that affect the short circuit behavior rise time alsoreferred to herein as a characteristic curve.

In adjusting the behavior of the smart dynamic circuit breaker theprocessor adjusts the tripping parameters to match the PV systemcharacteristic curve at the current time, during a changing impedanceand short circuit profile for the PV system. Each circuit breaker has afamily of behavior curves that are a graphical representation of thecircuit breaker's response to a particular current level and the circuitbreaker's response behavior. The processor picks the circuit breakerresponse time behavior curve that most closely matches the PV system'sshort circuit response at a given time. The processor samples the shortcircuit response of the PV system periodically and periodically adjuststhe behavior smart dynamic circuit breaker that matches one of aplurality of behavior curves for the smart dynamic circuit breaker. Inanother particular illustrative embodiment of the invention, The smartdynamic circuit breaker has programmable parameters that include but arenot limited to Continuous Amps (Ir). Long-Time Delay, Short-Time Pickup,Short-Time Delay, Instantaneous Pickup and Ground Fault Pickup, whichare adjusted based on the characteristic curve for the smart to matchthe current short circuit current determined by the processor during theperiodic short circuits monitored by the processor. Each setting affectsthe behavior curve for the smart circuit breaker.

A protection relay for an electrical switching apparatus for a loadincludes a number of voltage sensors structured to sense voltage appliedto the load, a number of current sensors structured to sense currentflowing to the load, and a processor cooperating with the number ofvoltage sensors and the number of current sensors. The processordetermines a fault current available at the load during the puked shortcircuit. An output cooperates with the processor. The output isstructured to output the determined fault current and a number ofincident energy at the electrical switching apparatus, and a personalprotective equipment level operatively associated with the electricalswitching apparatus. The processor determines from the determined faultcurrent the number of the incident energy at the electrical switchingapparatus, and the personal protective equipment level operativelyassociated with the electrical switching apparatus. U.S. Pat. No.8,493,012 B2 Protection relay, electrical switching apparatus, andsystem for determining and outputting fault current available at a loadand incident energy or personal protective equipment level operativelyassociated therewith, which is incorporated by reference in its entiretyherein, discloses a protection relay for an electrical switchingapparatus for a load includes a number of voltage sensors structured tosense voltage applied to the load, a number of current sensorsstructured to sense current flowing to the load, and a processorcooperating with the number of voltage sensors and the number of currentsensors. The processor determines a fault current available at the load.An output cooperates with the processor. The output is structured tooutput the determined fault current and a number of incident energy atthe electrical switching apparatus, and a personal protective equipmentlevel operatively associated with the electrical switching apparatus.The processor determines from the determined fault current the number ofthe incident energy at the electrical switching apparatus, and thepersonal protective equipment level operatively associated with theelectrical switching apparatus.

A photovoltaic system is disclosed, the system including but not limitedto a photovoltaic array of photovoltaic cells (solar cells) mounted on aphoto reactive back plane; a programmable dynamic programmable circuitbreaker for electrically providing a pulsed 100 microseconds durationshort circuit to a set of photovoltaic system electrical outputs,wherein a response time for the smart dynamic programmable circuitbreaker is more than 1 millisecond when responding to a short circuit; aprocessor in data communication with a computer readable mediumcontaining a computer program comprising instructions that when executedby the processor perform functions that control the smart dynamicprogrammable circuit breaker, the computer program including but notlimited to instructions to command the smart dynamic programmablecircuit breaker to initiate the 100 microsecond pulsed short circuit onelectrical outputs of the programmable photovoltaic system; instructionsto measure a current magnitude and current rise time of the smartphotovoltaic system outputs during the 100 microsecond pulsed shortcircuit; and instructions to select a behavior curve from a plurality ofsmart dynamic programmable circuit breaker behavior curves 10% above thecurrent magnitude and current rise time during the pulsed short circuit,that most closely matches the measured magnitude and current rise timeof the photovoltaic system during the pulsed short circuit. In anotherparticular illustrative embodiment of the invention, the photo reactiveback plane is reflective so that sunlight that passes by thephotovoltaic array is reflected back onto the photovoltaic cells forgenerating additional voltage from the photovoltaic array. In anotherparticular illustrative embodiment of the invention, the photo reactiveback plane is phosphorescent so that sunlight that passed by thephotovoltaic array generates additional light back onto the photovoltaiccells for generating additional voltage from the photovoltaic array. Inanother particular illustrative embodiment of the invention, the pulsedshort circuit duration is 100 microseconds and a minimum reaction timethe smart dynamic programmable circuit breaker is 500 microseconds sothat the smart dynamic programmable circuit breaker cannot react to thepulsed short circuit duration.

In another particular illustrative embodiment of the invention, aphotovoltaic system is disclosed, the system including but not limitedto a photovoltaic array of photovoltaic solar cells; a smart dynamicprogrammable circuit breaker for electrically providing a pulsed 100microseconds duration short circuit to a set of photovoltaic systemelectrical outputs, wherein a response time for the smart dynamicprogrammable circuit breaker is more than 1 millisecond when respondingto a short circuit; and a processor in data communication with acomputer readable medium containing a computer program comprisinginstructions that when executed by the processor perform functions thatcontrol the smart dynamic programmable circuit breaker, the computerprogram including but not limited to instructions to command the smartdynamic programmable circuit breaker to initiate the 100 microsecondpulsed short circuit on electrical outputs of the smart photovoltaicsystem; instructions to measure a current magnitude and current risetime of the smart photovoltaic system outputs during the 100 microsecondpulsed short circuit; and instructions to select a behavior curve from aplurality of smart dynamic programmable circuit breaker behavior curves10% above the current magnitude and current rise time during the pulsedshort circuit, that most closely matches the measured magnitude andcurrent rise time of the photovoltaic system during the pulsed shortcircuit.

In another particular illustrative embodiment of the invention anapparatus is disclosed, the apparatus including but not limited to aphotovoltaic array of photovoltaic solar cells; and a photo reactiveback plane, wherein the photovoltaic cells are mounted onto the photoreactive back plane. In another particular illustrative embodiment ofthe invention the photo reactive back plane is reflective so thatsunlight that passes by the photovoltaic array is reflected back ontothe photovoltaic cells for generating additional voltage from thephotovoltaic array. In another particular illustrative embodiment of theinvention the photo reactive back plane is phosphorescent so thatsunlight that passed by the photovoltaic array generates additionallight back onto the photovoltaic cells for generating additional voltagefrom the photovoltaic array.

1. A system, the system comprising: a photovoltaic array of photovoltaicsolar cells mounted on a photo reactive back plane; a smart dynamicprogrammable circuit breaker for electrically providing a pulsed 100microseconds duration short circuit to a set of photovoltaic systemelectrical outputs, wherein a response time for the smart dynamicprogrammable circuit breaker is more than 1 millisecond when respondingto a short circuit; and a processor in data communication with acomputer readable medium containing a computer program comprisinginstructions that when executed by the processor perform functions thatcontrol the smart dynamic programmable circuit breaker, the computerprogram comprising: instructions to command the smart dynamicprogrammable circuit breaker to initiate the 100 microsecond pulsedshort circuit on electrical outputs of the smart photovoltaic system;instructions to measure a current magnitude and current rise time of thesmart photovoltaic system outputs during the 100 microsecond pulsedshort circuit; and instructions to select a behavior curve from aplurality of smart dynamic programmable circuit breaker behavior curves10% above the current magnitude and current rise time during the pulsedshort circuit, that most closely matches the measured magnitude andcurrent rise time of the photovoltaic system during the pulsed shortcircuit.
 2. The system of claim 1, wherein the photo reactive back planeis reflective so that sunlight that passes by the photovoltaic array isreflected back onto the photovoltaic cells for generating additionalvoltage from the photovoltaic array.
 3. The system of claim 1, whereinthe photo reactive back plane is phosphorescent so that sunlight thatpassed by the photovoltaic array generates additional light back ontothe photovoltaic cells for generating additional voltage from thephotovoltaic array.
 4. The system of claim 1, wherein the pulsed shortcircuit duration is 100 microseconds and a minimum reaction time thesmart dynamic programmable circuit breaker is 500 microseconds so thatthe smart dynamic programmable circuit breaker cannot react to thepulsed short circuit duration.
 5. A system, the system comprising: aphotovoltaic array of photovoltaic solar cells; a smart dynamicprogrammable circuit breaker for electrically providing a pulsed 100microseconds duration short circuit to a set of photovoltaic systemelectrical outputs, wherein a response time for the smart dynamicprogrammable circuit breaker is more than 1 millisecond when respondingto a short circuit; and a processor in data communication with acomputer readable medium containing a computer program comprisinginstructions that when executed by the processor perform functions thatcontrol the smart dynamic programmable circuit breaker, the computerprogram comprising: instructions to command the smart dynamicprogrammable circuit breaker to initiate the 100 microsecond pulsedshort circuit on electrical outputs of the smart photovoltaic system;instructions to measure a current magnitude and current rise time of thesmart photovoltaic system outputs during the 100 microsecond pulsedshort circuit; and instructions to select a behavior curve from aplurality of smart dynamic programmable circuit breaker behavior curves10% above the current magnitude and current rise time during the pulsedshort circuit, that most closely matches the measured magnitude andcurrent rise time of the photovoltaic system during the pulsed shortcircuit.
 6. An apparatus, the apparatus comprising: a photovoltaic arrayof photovoltaic solar cells; and a photo reactive back plane, whereinthe photovoltaic solar cells are mounted onto the photo reactive backplane.
 7. The apparatus of claim 6, wherein the photo reactive backplane is reflective so that sunlight that passes by the photovoltaicarray is reflected back onto the photovoltaic cells for generatingadditional voltage from the photovoltaic array.
 8. The apparatus ofclaim 6, wherein the photo reactive back plane is phosphorescent so thatsunlight that passed by the photovoltaic array generates additionallight back onto the photovoltaic cells for generating additional voltagefrom the photovoltaic array.